In average, most people spend eight hours a day on bed. In other words, everybody's head has to rest on a pillow for one third of a day. A comfortable pillow that has good ventilation feature becomes the most important factor of having a good sleep. The common pillow is made of polyester that fails to well support the neck portion of the user and to provide sufficient ventilation to the user's head.
In recent years, buckwheat hulls are used as the filler of pillow or cushion. Since the buckwheat hulls have excellent resilience strength that can prevent fragmentation under pressure, the buckwheat hulls are good filler for pillows that can provide remarkable ventilation, that the cool and refreshing buckwheat pillow enables the user's head to comfortably rest thereon. Furthermore, the user may shape the pillow to fit his or her head shape in order to achieve a better support to his or her head and neck. However, such buckwheat pillows are not so popular in market and being accepted by the consumers. It is because the granulated buckwheat hulls are movable due to compression or pressure. Therefore, as shown in FIG. 1, most users find that the buckwheat hulls filled inside the fiber pillow bag will be easily shifted aside due to the numerous turning movement and the weight of the user's head, so that finally the bottom portion of the user's head will directly contact with and press on the mattress surface that causes very uncomfortable feeling. In addition, the ventilative feature of the buckwheat pillow may also provide reverse effect in winter season, that the user may feel too cool to sleep thereon.
Furthermore, it is well known that infrared is a kind of electromagnetic wave having great benefit to human health. All nature electromagnetic waves are classified according to their wave length and frequency. Sunlight generally comprises 7% of destroying ray including .alpha.-ray, X-ray and ultraviolet ray, 13% of visible light, and 80% of infrared ray and micro-ray. The infrared ray can also be further classified as the intimate infrared ray having a wave length of 0.76 to 1.5 .mu.m, the middle infrared ray having a wave length of 1.5 to 5 .mu.m, the far-infrared ray having a wave length of 5 to 100 .mu.m, and the super far infrared ray having a wave length of 100 to 1000 .mu.m.
We know that 60 to 70% of human body is constituted by water molecules and 30 to 40% of organic molecules such as protein. Both the water molecules and the organic molecules selectively reflect, absorb and transmit the infrared radiation that has a wave length of 5-25 .mu.m, wherein 60% of the entire radiation energy discharged by human body has a wave length of 8 to 15 .mu.m. Since the human body can emit far-infrared ray of the above wave length, the human body is thus capable of absorbing far-infrared ray of such wave length. In other words, the best wave length of the far-infrared radiation for human absorption is 8 to 15 .mu.m. When human body absorbs the far-infrared ray having the wave length of 8 to 15 .mu.m, the absorbed far-infrared ray will cause the water molecules inside the human body generating resonance that may activate the water molecules to enhance the bonding ability among the water molecules so as to further activate the big organic molecules, so that the animal cells will perform high vibrating energy level. Since the animal cells will generate resonance effect, the far-infrared heat energy would be transmitted to a deeper portion under the human skin, so as to increase the heat temperature of such deep layer under the human skin. In which the heat generated will emit outwardly that would cause the blood vessels of human being to expand, so as to advance the blood circulation, to strengthen the metabolism among the body tissues, to remove the obstacle of body fluid, to enhance the regeneration ability, to enhance the human immunity, and to regulate the unusual exciting condition of human nerves system.
Some natural substances such as far-infrared ceramics can discharge far-infrared radiation. If such far-infrared emission substances can be used as the constructing material of the pillow, the user can thus absorb the far-infrared radiation to advance his or her health during sleeping.